The present invention relates to tree trimmers in general. More specifically to an apparatus that is self-propelled and climbs trees while cutting fronds or branches with revolving blades.
Previously, many types of mechanical devices have been used for providing a means to climb and remove limbs of standing trees.
A search of the prior art did not disclose any patents that possess the novelty of the instant invention, however the following U.S. patents are considered related:
Clouston in U.S. Pat. No. 5,983,966 teaches a self-propelled tree pruning apparatus using a cutting tool with helical edges. The invention includes a frame, a pair of driven wheels and a pair of hugger wheels that are rotatably attached to the frame. Pneumatic air bags urge the hugger wheels toward the driven wheels, and the cutting tool is attached to a drive shaft which is also attached to the frame and is movable along three axes. A self-powered engine drives both the cutting tool and the driven wheels. The drive engine is throttled back to an idling speed and the pressure is released on the air bag when the device is to descend to the ground.
U.S. Pat. No. 5.975,168 issued to Ericksson is for a trimming device that utilizes a harvester head positioned at a pre-selected transverse position relative to a tree trunk. A control device is movably connected to a tree trimming member selecting a transverse position relative to the tree trunk. An actuator urges a tree trunk engaging portion into engagement with the tree and the trimming member at the pre-selected transverse position.
Barnhill, et al. in U.S. Pat. No. 5,524,685 discloses a debarking/declimbing apparatus having a rotatably driven spool device that removes bark as the tree parts are moved lengthwise across its axis. The spool device consists of a rotor which includes tooth elements with two spools used in concert. The debarking elements may be fixed in helical form or may be flexibly mounted and capable of assuming a near helical form.
Fuminao in U.S. Pat. No. 4,690,184 teaches a tree pruning machine having a cutting unit mounted on a frame and wheels elevating vertically. A first member has drive wheels mounted on its lower portion that are driven by an engine; a chain saw is also rotated by the engine. A branch sensing member projects forward temporarily stopping the drive toward the upward direction of a standing tree.
U.S. Pat. No. 4,527,603 issued to Hori is for an automatic lopping machine which has a body with a drive unit, a chain saw and a number of drive wheels. An auxiliary unit includes idle wheels connected together with the main body so as to encircle a tree trunk. The drive unit is used to drive the chain saw and the drive wheels when the machine revolves helically around the tree trunk when the machine ascends a tree trunk.
Baxter Jr. in U.S. Pat. No. 3,545,509 discloses a tree harvester that converts standing trees into chips by delimbing the tree from the bottom to the top, debarking the trunk from the top to the bottom, and progressively converting the tree trunk into chips from the top down. The device uses chain saws with knives that produce chips with long fibers and direct the chips upwardly out of the path of the knives.
Many attempts have been made to trim trees remotely without the necessity of actually climbing the tree. This utility is particularly useful when removing fronds from palm trees, as it has always been very difficult to trim palms or cycads since the fronds have sharp needle like barbs on their ends that are connected to husks. Additionally, considerable dust, dirt, trash and even rodents such as tree rats live in the tops of these type of tree. The common procedure for trimming and/or dressing palm trees is to manually cutoff and remove the frond adjacent to the palm husk. This operation requires a mechanical hoist or some other method of lifting the trimmer to the area that is to be trimmed. In some cases, the trimming is manually accomplished by actually climbing the tree using climbing gear that is well known in the art. Regardless of how the work is accomplished, it is dangerous and liability increases the cost. Also, the work is labor intensive and the initial cost of elaborate lifting equipment is fairly high. Therefore the primary object of the invention is to utilize a mechanical, self-propelled trimmer that climbs the tree and trims the fronds using a revolving set of blades, which allows an operator to remain on the ground a safe distance away and remotely guide the trimmer in its climbing speed and its depth of cut.
An important object of the invention is directed to its safety aspect since the operator is completely removed from the area where the fronds fall, the operator is not precariously positioned during any phase of the trimming operation.
Another object of the invention is that the most current automation is employed, using motors that are many times smaller and more powerful than prior art equipment and are compact and deliver energy density exceeding internal combustion engines.
Still another object of the invention is the speed that a tree can be trimmed relative to the manual process. The operator simply attaches the inventive self-propelled climbing tree trimmer around the base of the tree and connects the trimmer to a utility power source or to a portable generator and stands clear while controlling the movement of the trimmer and depth of cut from a safe remote location on the ground. It is easily understood that the time to trim the tree is reduced to a fraction of the manual process.
Yet another object of the invention is the flexibility of the trimmer. Although the timmer is primarily designed to be used with palm trees or cyaids it may also be used on other trees that have small branches which are typically trimmed while the tree is still growing.
A further object of the invention is the ability of the trimmer to leave a palm tree with a uniform appearance as the uneven husks left on the tree after trimming in a conventional manner are completely eliminated, thus causing all adjacent trees to have the same uniform outward appearance. The invention is able to deliver a uniform, visual outside shape of the tree trunk with reliable repetition.
These and other objects and advantages of the present invention will become apparent from the subsequent detailed description of the preferred embodiment and the appended claims taken in conjunction with the accompanying drawings.